Re: logical decoding : exceeded maxAllocatedDescs for .spill files

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
Cc: Noah Misch <noah(at)leadboat(dot)com>, Amit Khandekar <amitdkhan(dot)pg(at)gmail(dot)com>, Alvaro Herrera from 2ndQuadrant <alvherre(at)alvh(dot)no-ip(dot)org>, Andres Freund <andres(at)anarazel(dot)de>, Juan José Santamaría Flecha <juanjo(dot)santamaria(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>, Robert Haas <robertmhaas(at)gmail(dot)com>, Thomas Munro <thomas(dot)munro(at)gmail(dot)com>, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>
Subject: Re: logical decoding : exceeded maxAllocatedDescs for .spill files
Date: 2020-01-10 00:40:12
Views: Raw Message | Whole Thread | Download mbox | Resend email
Lists: pgsql-hackers

I wrote:
> ReorderBuffer: 223302560 total in 26995 blocks; 7056 free (3 chunks); 223295504 used

> The test case is only inserting 50K fairly-short rows, so this seems
> like an unreasonable amount of memory to be consuming for that; and
> even if you think it's reasonable, it clearly isn't going to scale
> to large production transactions.

> Now, the good news is that v11 and later get through
> just fine under the same restriction.
> So we did something in v11 to fix this excessive memory consumption.
> However, unless we're willing to back-port whatever that was, this
> test case is clearly consuming excessive resources for the v10 branch.

I dug around a little in the git history for backend/replication/logical/,
and while I find several commit messages mentioning memory leaks and
faulty spill logic, they all claim to have been back-patched as far
as 9.4.

It seems reasonably likely to me that this result is telling us about
an actual bug, ie, faulty back-patching of one or more of those fixes
into v10 and perhaps earlier branches.

I don't know this code well enough to take point on looking for the
problem, though.

regards, tom lane

In response to


Browse pgsql-hackers by date

  From Date Subject
Next Message Michael Paquier 2020-01-10 00:45:46 Re: pgbench - use pg logging capabilities
Previous Message Alvaro Herrera 2020-01-10 00:27:42 Re: pgbench - use pg logging capabilities